Scalafix review
A free, CI-ready Scala refactoring tool with syntactic and semantic rules.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
Scalafix is an open-source refactoring and linting tool for Scala teams that want automated code changes and diagnostics across a project. It supports Scala 2.12, Scala 2.13, and Scala 3, with built-in rules for import organization, unused code, syntax, and type annotations. Teams can run it locally through its command-line interface or sbt integration, making it suited to developers and CI workflows that need consistent refactoring checks.
Its strongest capability is the combination of syntactic and semantic rules. Syntactic rules can lint and rewrite source files, while semantic rules use SemanticDB and compiler information for decisions that require more context. Scalafix supports fixing individual files or recursively visited directories, along with dry runs, stdout output, diffs, exclusions, and configuration options. Custom rules can be defined locally or published to Maven Central, giving teams a way to extend the tool beyond its built-in rules.
Scalafix is free and open source, with integrations for sbt, scala-cli, Mill, Gradle, Maven, and Mega-Linter. Its sbt support includes project-wide and multi-project tasks, and CI check mode can enforce compliance without applying changes. The main trade-off is focus: Scalafix is designed for Scala rather than a broad set of programming languages, and it runs as a local developer tool instead of a hosted service. Scala teams that want repository-wide refactoring and CI enforcement should consider it; organizations seeking a hosted refactoring platform or wider language coverage should look elsewhere.
Scalafix pros and cons
- Where it wins
- Syntactic and semantic rules support automated code changes
- Project-wide sbt tasks and CI check mode support enforcement
- Custom rules can be published to Maven Central or defined locally
- Where it doesn't
- Core language coverage is limited to Scala
- Local desktop tooling is not a hosted SaaS service
- Several integrations rely on externally maintained plugins
Scalafix fact sheet, pricing and score →
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